KVM: PPC: Book3S HV: Remove bogus update of physical thread IDs

When making a vcpu non-runnable we incorrectly changed the
thread IDs of all other threads on the core, just remove that
code.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>